Electric signaling apparatus for cars on electric and other railways



H. SCHAUB AND 0. KUNZLI.

ELECTRIC SIGNALING APPARATUS FOR CARS 0N ELECTRIC AND OTHER RAILWAYS.

APPLlCATlON FILED APR. 14. 1919.

1,381,620.. Patented June 7,1921.

*1 SCEAUB AND CARL KTl'NZLI, OF ZURICH, SWITZEBL.

ELECTRIC SIGNALING APPTUS FOR CARS ON ELECTRIC AND OTHER RAILWAYS.

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Specification of Letters Patent.

Patented June a, 1921.

Application filed April 14, 1919. Serial No. 289,796.

To all whom it may concern:

Be it known that we, HANS SCHAUB and CARL KfiNzLI, citizens of Switzerland, residing at Zurich, Switzerland, have invented certain new and useful Improvements 1n Electric Signaling Apparatus for Cars on Electric and other Railways, of which the following is a specification.

The present invention relates to a three pole electric mercury switch in which the making and breaking of the circult takes place 1n the completely closed ofl:' cavity of a plate mounted on a rotational axis. ereby all formation of sparking at a point accessible to the outer air is avoided. This renders the switch particularly suitable for use in locations in which the surrounding air contains explosive gases, for example in mines, and in explosive and carbide manufacturing plants, and the like.

The said cavity has the shape of a passage forming a right angle, and is about half full of mercury, the passage being closed off at each end by a contact support. Such a contact support is also provided at the apex of the right angle. The device is further arran ed that at a switching position either one or 51c other of the branches or arms of the passage is horizontal, and the mercury contained in the passage conductively connects the contact support at the outer end of this branch with the central contact support at the apex of the right angle, while the third support is out of contact with the mercury. All three contacts are permanently connected 7 with the circuit. Themaking and breaking of the circnit takes place only in the said passage between the mercury and one of the contact supports closing off the ends of the passage, thus not at parts exerting friction on each other. The present switch is hence characterized by particularly great resistance to wear and certainty of operation. A switch constructed in accordance with the invention was subjected to more than one million switching operations within a period of about two months without suiferin injury or failing tooperate. Such a switc is especially well suited for places in which numerous switching operations must be made and where absolute reliability is required, for example, as in cutting ofl or reversing the circuit which serves for announcing stop andstart signals in street railwa s.

An embodiment of the subject of the 1nvention is shown by way of example on the drawings, in which Figure 1 is a front elevation of the switch.

Fig. 2 is a lateral elevation, and Fig. 3 a sectional detail.

16 isya triangular plate of insulating material. It has two chambers 17 and 18 superposed at right angles and intersecting at the apex of the angle, and a quadrangular perforation 16 to be mounted on a quadrangular portion of a rotational axis 16 and to rotate therewith. At the point of intersection of chambers 17 and 18 and at the outer end of each chamber there is inserted metal screw threaded plugs 10, 10 and 10 containing the contact screws 11, 11 and 11 The axis 16 has an extension 3 journaled ina housing 2, which passes through the wall 1 of the car. It is provided at its inner end (Fig. 2 at the left) as also between the outer side of the wall and plate 16, with fixed lever arms 4 and 13, to which are coupled operating rods 6 and 6 By means of the rods, the plate 16 can be rotated and one or the other of the chambers 17 and 18 may be brought into the horizontal position. Hence, the metal screw threaded plug 10 which is-constantly in contact with the mercu is connected bythe latter either with the p ug 10 or 10 The making and breaking of the circuit takes place in the closed chambers 17 and 18 of plates 16, that is, between the mercury and one or the other of the plugs 10 and=1O As a result, formation of sparking can take place here only and, by reason of the small amount of air contained in said cavity, the amount of the sparking is very limited, in any case the sparking does not occur on the outside. If a switch of. the type described is not used for announcin signals in railway cars, but for connectin n small motors, heating and light plants t is evident that itmay be essentially simplified, that is as regards the ,parts serving to actuate it. The embodiment shown of the latter is recommended, since it permits of announcin optical start and stop signals by means of the same arm and hand movement as necessar for the hitherto customary bell signals. erein the conversion from one system to the other is considerably facilitated, and for the, new onegreatease of manipulation from the beginning.

Claims: 1. A three pole electric mercury switch,

including a rotary horizontal axis, a plate mounted on said axis and provided with an angular chamber located in a plane perpendicular to the axis and about half filled with mercury, conducting plugs closing the ends of the chamber, means for connecting said plugs with an electric circuit, and a third plug provided at the apex of said chamber and being constantly connected with the mercury within the chamber.

2. A switch of the kind defined by claim 1 in which the axis is provided at its opposite ends with lever arms, pull rods connected to said lever arms, and a counterweight secured to said axis.

3. A switch comprising a horizontal rotatable axle, a plate fixed to said axle and having a plurality of communicating chambers arranged at angles to each other, a metal screw-threaded'plug closing the outer ends of each of said chambers, a third plug arranged at the point of angle between said chambers, a body of mercury substantially filling one of said chambers and movable into either of said chambers when the plate is shifted for causing either'one of the first named plugs" to be electrically connected to the third plug, a lever armfixed to said axle and a counterweight also secured to said axle.

In testimony whereof we have afiixed our 

